"Peter is in front of me."
Translation:मेरे आगे पीटर है ।
Is "mere" here in the genitive (possessive) plural, like how it was described in "mere paas" when we learned "to have" in the lightbulb to one of the earlier lessons? Or was that a simplified explanation and in reality it's the oblique singular (or plular) masculine of "mera"?
And either way, why is the genitive used instead of the oblique/dative? Is this like in Russian, German and other languages, where you just have to know which case goes with which preposition (postposition)? If so, are Hindi postpositions split between genitive and oblique/dative control?
मेरा is the genitive case form of मैं (I). मेरे, as used in मेरे आगे or मेरे पास, is the (masculine) oblique form of the genitive मेरा. मेरे is also the (masculine) plural of मेरा as used in 'ये मेरे भाई हैं' (These are my brothers).
Technically, Hindi is supposed to have inherited the eight cases (nominative, accusative, instrumental, dative, ablative, genitive, locative and vocative) of Sanskrit. But in reality, the case system is much simpler. For nouns, the function of cases is mostly taken over by postpositions. For instance, the genitive case is marked by the postpositions का, की, के. Similarly, the dative case is marked by को, the instrumental case by से and so on. So, nouns effectively only have three cases - direct (where it is not an object of a postposition), oblique (when it is an object of a postposition) and vocative (when it is directly addressed).
Pronouns, however, do change form in different cases and postpositions are not used with them. However, as a result of syncretism, their forms under multiple cases may look the same. For example, मुझे is both the accusative and dative of मैं.
आगे is an adverb/adjective. It is 'के आगे' that is a compound postposition.
Compound postpositions are formed by combining the oblique forms of का (ie, के and की) with another word and are grammatically somewhat tricky territory. The problem is that some of these compound postpositions don't necessarily mark the genitive. For example, the compound postposition 'के द्वारा' (using/by) is interchangeable with the postposition marking the instrumental case, से.
As I said, postpositions cannot be used with pronouns. So, you can't say 'मैं के द्वारा' or 'आप के द्वारा'. Instead, we use the oblique genitive forms of the pronouns (मेरे and आपके respectively) along with the second word of the compound postposition - 'मेरे द्वारा' and 'आपके द्वारा' (with आपके being a single word). Now, 'मेरे द्वारा'/'आपके द्वारा' as a whole may be considered to be one of the instrumental case forms of मैं/आप.
Note: The fact that it has oblique forms or inflects according to gender makes का/की/के unique among postpositions and there is some debate as to its status.
Good catch. The word is actually मुझपे/ मुझपर. But, more often than not, it is separated out into two words for simplicity. The same is true for other locative case forms- आप में instead of आपमें and so on.
Note: In colloquial speech, some people even use the forms 'मेरे पे', 'मेरे में' etc even though there is no compound postposition of the form 'के पर' or 'के में'.
I'm so happy with this explanation. Never realized that ko is the dative. And that muzhe is both dative and accusative. Is there a list somewhere? Do wish Duolingo had some reference pages for grammar. Not that I have any idea what you can do with lingots but I just donated two, haha.